1. Field of the Invention
This invention relates in general to certain new and useful improvements in stringed musical instruments and, more particularly, to stringed musical instruments of the type having an elongate neck and a body and which are capable of generating electrical sounds in response to vibration of strings extending across that body and with removable fingerboards on the neck.
2. Brief Description of the Related Art
Most stringed musical instruments usually include an elongate neck with a body having a resonant cavity at one end and a head at the other end of the neck. Strings extend across the body of the musical instrument and, when vibrated, either by a bow or fingers or the like, the body will generate musical sounds. Instruments of this type usually include guitars, bases, violins, cellos and the like.
Many musical instruments are based on the generation of the sound through the instrument itself. Thus, in the case of a conventional guitar, the actual vibration of the string, which is usually in the form of a thin wire, with respect to a resonant cavity causes a generation of the desired sound. However, many of these instruments are electrified and use one of more transducers to generate the desire sounds in response to vibration of the strings.
In several of these musical instruments, each of the wires, referred to as "strings", are stretched under tension between the resonant body and the head. Further, in most of these instruments, the strings are stretched between a pair of projections in proximity to the neck, typically referred to as the "bridge" and the "neck". These two elements define the useful length of the strings and, hence, the sounds which are generated by those strings. Thus, by shortening the length between a point where the string engages the fingerboard to the bridge, the sound can be altered.
The aforesaid musical instruments are effectively divided into two major types of instruments in which the useful or active length of the string is adjusted by pressing the string against a fingerboard on the upper surface of the neck. In generally all cases, the fingerboard is an integral part of the neck of the musical instrument, or otherwise it is permanently affixed to the neck. However, some musical instruments are provided with frets on the fingerboard and are typically referred to as "fretted" musical instruments which allows the user to engage the string of the instrument against a-fret so that a useful length is achieved equal to the distance between the fret and the bridge. This will create a note of precisely defined timber and also of metallic character. Other instruments without frets are often referred to as "fretless" instruments and the useful length of the string is determined by the distance between the point at which the player keeps the string pressed against the fingerboard and the bridge. In absence of the fret, there is a lack of metallic quality to the sound and the sound also has a softer character.
It may be appreciated that for certain musical pieces, fretted instruments are desired and for other musical pieces, fretless instruments are desired. However, since there is no convenient means for altering an instrument with frets, or without frets, the average musician must constantly carry at least two such instruments, one containing frets and one without frets. In particular, for the base guitar and the slide or so-called "bottle neck" six-string guitar, each player almost inevitably carries at least two musical instruments for this purpose. However, this limits the player in attaining the desired musical flexibility while retaining the feel and capabilities of a preferred instrument.
There have been several attempts in the prior art to provide stringed musical instruments in which frets can be used or withdrawn. In U.S. Pat. No. 4,267,936 to Mouton, there is provided a stringed musical instrument having retractable frets. In this case, an electric base guitar is provided with retractable frets, such that in one position, the frets are flush with the surface of the fingerboard and, in another position, the frets are raised above the surface of the fingerboard. The neck of the instrument has an inclined slope on one side causing wedge shaped feet on the frets to ride on this inclined slope for raising and lowering the frets.
There is a also a proposed stringed musical instrument having retractable frets described in U.S. Pat. No. 4,772,260 to Pigozzi. In this case, a guitar has a fingerboard in which the frets are slidably disposed within the neck holding the fingerboard. A rather complex mechanism, including cams, springs and a rotatable shaft, are provided for raising and lowering the frets. While this type of instrument may be attractive in theory, as a matter of practicality, the mechanism used is quite complex and significantly adds to the overall weight, and certainly to the cost of the musical instrument.
In each of the aforesaid prior art systems for providing frets and effectively removing frets, they would be inherently slow and cumbersome. Consequently, these systems are not effective for the average musician who desires to quickly change from a fretted instrument to a fretless instrument. As a result, systems of the types proposed in these patents have not been effectively used.